The Girl, the Dragon, and the Wild Magic (The Rhianna Chronicles, Book 1)

Rhianna is clumsy and poor at schoolwork, but when a wizard with a long beard appears, she discovers that she has the wild magic that may be able to save her village from the dragon.

Long Synopsis:

Rhianna is failing out of magic school. She's rather clumsy, even though she tries her best. After she causes her biggest mess ever, a wizard appears with some astonishing news. Rhianna's magic is, in fact, stronger than anyone else's. She's a Wild Talent, which means that she possesses a pure form of magic that is full of power and energy. The hitch? Well, its very hard to control wild magic. And it tends to suck up all the other magic around it. So when a dragon comes to town, it's up to Rhianna to save the day.